“[The very large growth of hedge funds in the sovereign debt market] does make you nervous that if there was a period of volatility and haircuts in repo markets went up, or there was some disruption in repo markets, you could get a rapid unwind… These trades are very low risk for each hedge fund, but when they are all doing something similar, there could be a systemic overlay.” – Tiff Macklem – Governor of the Bank of Canada, CNBC policy panel at the ECB Forum on Central Banking 1 July 2026

Periods of elevated leverage in sovereign debt markets create a deceptively tranquil surface over a deeply interdependent funding structure. When a single short-term market – the repurchase agreement, or repo, market – becomes the principal source of leverage for a large cohort of hedge funds all pursuing similar trades, the system acquires a hidden fragility that is not obvious from the risk profile of any individual fund.^1,16 The central concern is not whether a particular basis trade or relative value strategy is mispriced, but whether the plumbing of the market can withstand a sudden repricing of funding terms or a temporary disruption in collateralised lending.^1,10,16

The structural rise of hedge funds in sovereign debt

Over the past decade, sovereign bond markets have undergone a quiet but profound shift in their investor base. In multiple jurisdictions, hedge funds have moved from the periphery of government bond trading to become central liquidity providers and large holders of sovereign paper.^12,24 In Canada, staff analysis shows that since 2020 hedge funds have become the largest investor class at Government of Canada bond auctions after primary dealers, absorbing a rising share of issuance as public debt has grown.^6,29 Similar dynamics are visible in euro area government bond markets, where hedge funds’ share of secondary market trading volumes roughly doubled between 2018 and 2023, reaching more than half of turnover on at least one leading electronic platform.¹⁵

This transformation reflects several intertwined drivers. First, regulatory reforms after the global financial crisis constrained banks’ ability and willingness to run large proprietary trading books, reducing their capacity to warehouse interest rate risk.¹² Second, years of low yields pushed asset managers and hedge funds towards strategies that rely on leverage to generate returns from small relative value opportunities. Third, governments worldwide have issued significantly more debt, creating a structural need for marginal buyers capable of absorbing large flows.^8,10,24 Hedge funds, operating with flexible mandates and aggressive leverage models, have stepped into this role, financing their holdings predominantly via short-term repos.^6,16

From a day-to-day market functioning perspective, this shift has clear benefits. Hedge funds’ trading activity has supported strong auction performance, enhanced secondary market liquidity and contributed to tighter bid-ask spreads.^6,12,15 The presence of fast-moving, highly levered participants can help intermediate large flows, especially when other investors are more price-sensitive or less active. Yet the same features that support liquidity in normal times – high leverage, short-term funding and correlated strategies – become channels of amplification when stress hits.¹⁶

Repo leverage: the benign mechanics and hidden sensitivity

The repo market is the core funding mechanism behind leveraged sovereign debt strategies. A repo is economically akin to a collateralised loan: one party sells a security, typically a government bond, while simultaneously agreeing to repurchase it at a slightly higher price on a specified future date.^14,26 The difference in prices reflects an interest rate on the cash lent, and the transaction is structured to protect the lender through a haircut – the margin between the market value of the collateral and the cash advanced.^14,26

In normal conditions, haircuts are low and funding is abundant. Hedge funds can borrow against high-quality sovereign bonds with minimal margin, rolling short-term repos day after day at predictable rates. A relative value fund might, for example, buy a Government of Canada bond and finance almost the entire position via overnight repo, hedging the interest rate risk with futures or swaps. The expected excess return is incremental and depends on small pricing basis, so the fund scales the trade using leverage. If the haircut is h and the fund’s equity capital allocated to the trade is E, a simple representation of the leverage ratio L is L = \frac{1}{h}\times\frac{\text{value of position}}{E}. With haircuts of only a few percentage points, L can become large even if each position appears well-collateralised.

From the standpoint of the individual hedge fund, risk management frameworks focus on market risk, liquidity buffers, counterparty exposures and potential margin calls, often supported by stress testing and scenario analysis.¹⁸ Under plausible shocks to yields or spreads, modelled losses can appear manageable; the repo market seems sufficiently deep and resilient, particularly in core sovereigns such as Government of Canada bonds or US Treasuries. That perception is reinforced by the behaviour of central banks, which routinely use repos and reverse repos as operational tools to implement monetary policy and manage short-term liquidity.^2,14

The problem arises from a mismatch between microprudential assessment and system-wide dynamics. Each fund models its own exposures and stresses based on assumptions about market liquidity, funding access and the behaviour of other participants. If many funds simultaneously rely on the same short-term collateralised lending channel and pursue strategies that are structurally similar, then the aggregate demand for funding and the potential for forced sales under stress can far exceed what any single institution anticipates.^5,16,17

Concentration, correlation and systemic overlays

Central bank research increasingly emphasises that systemic risk is not simply a function of individual institutions’ leverage or capital ratios, but of common exposures and position similarity.^5,17 In the Canadian banking system, studies decomposing systemic risk have highlighted the importance of both contagion through interconnections and common exposure to similar assets.^5,17 When portfolios overlap substantially, even diversified institutions can become collectively fragile.

In the context of hedge funds in sovereign debt markets, the systemic overlay arises from a combination of factors:

• Widespread use of relative value strategies that are structurally similar, such as cash-futures basis trades, asset swaps and cross-market arbitrage.^12,28
• Heavy reliance on short-term repo funding against sovereign collateral, with low haircuts in normal times.^6,14,16
• Concentration of positions in a limited set of highly liquid government bonds and associated derivatives, including G10 sovereigns.^3,10
• Reliance on common trading platforms, clearing arrangements and, in some jurisdictions, central counterparties for fixed-income repo.^14,26

When these elements align, the system can tolerate modest shocks, but becomes exposed to nonlinear dynamics under more severe stress. If volatility spikes and repo haircuts increase, leverage must fall mechanically. Borrowers either provide more collateral or reduce the size of their positions. For a leveraged hedge fund with positions financed at low haircuts, a sudden rise in h reduces the maximum sustainable leverage L, requiring either new equity capital – rarely available in real time – or rapid asset sales. If many funds are in this position simultaneously, the resulting sales can push prices down, triggering further margin calls in a procyclical loop.^16,18

This phenomenon was observed in condensed form during the US Treasury market turmoil of March 2020, where research attributes hedge funds’ reduction in Treasury exposures primarily to fund-level liquidity management and redemption pressures rather than regulatory constraints on dealers.¹⁸ Even though bilateral repo volumes and haircuts did not spike dramatically, funds stepped back from basis trades, closing positions and contributing to volatility.¹⁸ The episode serves as an empirical reminder that, under stress, investors’ behaviour can amplify price moves even when core market infrastructure technically remains open.

Volatility, haircuts and the mechanics of a rapid unwind

The scenario that worries policymakers builds on this logic but imagines a sharper shock. Suppose sovereign markets experience a period of elevated volatility driven by geopolitical events, fiscal concerns or abrupt shifts in rate expectations.^10,20 Repo lenders, seeking to protect themselves, raise haircuts and shorten tenors. As h increases, leveraged funds face a sudden deterioration in the economics of their trades. Positions that were previously marginally profitable after funding costs become uneconomic; more importantly, collateral requirements relative to available liquidity increase.

At that point, funds have several options: attempt to negotiate funding terms, allocate additional internal liquidity, or unwind trades. Because sovereign basis trades are often structured to be liquid and scalable, unwinding is technically straightforward – but if many funds choose to do so simultaneously, selling pressure rises sharply. Price moves then feed back into risk models, potentially generating further deleveraging and risk limits being hit. Dealers, concerned about their own balance sheets and capital constraints, may be unwilling to absorb the flow at tight spreads, causing liquidity to thin.^10,15,18

In an extreme case where there is a temporary disruption in repo markets – for example, operational issues at key intermediaries, cyber incidents affecting centralised platforms, or sudden regulatory changes – the feedback loop can accelerate. Funding dries up not only because haircuts increase, but because some funding channels are unavailable. Funds that cannot roll repos at all must unwind positions even if market prices are unfavourable, leading to a forced liquidation dynamic. The systemic overlay appears precisely because many institutions share the same funding mechanism and the same broad strategy template.

Central banks recognise that such dynamics could transmit stress from what appears to be a peripheral trading strategy into the backbone of the financial system: sovereign debt markets.¹⁶ Government bonds underpin monetary policy implementation, bank liquidity buffers and collateral frameworks. Dislocation in these markets, especially if prolonged, can impair the transmission of policy and heighten uncertainty across the financial system.^2,10,14

New players, old risks: non-bank debt market vulnerabilities

Policy speeches and financial stability reports from the Bank of Canada emphasise that the rise of non-bank financial intermediaries – hedge funds, private credit funds and others – brings both benefits and vulnerabilities.^4,8,10,16 These entities add flexibility, diversify sources of intermediation and reduce reliance on the regulated banking sector for capital and liquidity. At the same time, they operate under different regulatory frameworks, are less transparent to supervisors and may engage in leverage or maturity transformation in ways that are harder to monitor.^4,7,10,16

Recent official assessments identify three broad pressure points. First, leveraged trading by hedge funds in government bond markets, largely financed through repos.^10,16 Second, the rapid expansion of private credit, where loan quality, leverage and interconnectedness with banks and markets are more difficult to assess.^4,16 Third, stretched valuations and rising term premia in sovereign yields driven by high government debt issuance and persistent geopolitical uncertainty.^10,22

The concern is not that these developments are unsustainable per se, but that the risks may be growing faster than authorities’ ability to understand and mitigate them.^4,7 Monitoring infrastructures built for a bank-centric system are being asked to cover a larger and more complex perimeter. Data gaps, limited visibility into hedge fund portfolios and cross-border exposures complicate the assessment of systemic risk. Supervisors are therefore trying to triangulate risk using a combination of market data, supervisory intelligence and macroprudential models that decompose systemic risk into components such as contagion and common exposure.¹⁷

Evidence of rising concentration in sovereign debt exposures

Independent monitoring also points to growing concentration in hedge funds’ sovereign debt portfolios. In the United States, official data suggest that foreign sovereign debt exposures held by hedge funds reached all-time highs by 2024, with gross exposures to G10 sovereign debt and related derivatives expanding rapidly since 2022.³ A hedge fund monitor tracking foreign exchange and sovereign debt exposures reports that the ten largest hedge funds account for a substantial majority of total sovereign debt exposures, underscoring the degree of concentration at the top of the sector.³

Informal estimates in market commentary point to hedge funds collectively holding several trillion dollars’ worth of global sovereign bonds, with a particularly large share in US Treasuries.⁹ While such figures should be treated cautiously, they align with the qualitative message from central banks and international organisations: hedge funds have become major sovereign debt investors and liquidity providers in multiple jurisdictions.^8,10,24

In Canada, staff analytical work finds that hedge funds’ share of Government of Canada bond auctions has risen in tandem with the increase in issuance since 2019.^6,29 Funds have responded to higher issuance volumes due to business models that scale with trading size and leverage, and they appear willing to pay more for bonds than some traditional investors, helping auctions clear smoothly.^6,29 This contribution is valuable, but the same analysis highlights the dependence of these strategies on repo funding and the absence of a natural long-term anchor to the Government of Canada bond market, in contrast with institutions such as domestic pension funds or insurance companies.⁶

Debates on hedge funds’ net contribution to market stability

There is an active debate among policymakers and researchers about whether hedge funds’ growing role in sovereign debt markets is stabilising or destabilising. On one side, central bank blog analysis of euro area government bond markets finds little evidence that increased hedge fund presence structurally amplifies volatility in normal times.¹⁵ Hedge funds often provide liquidity during episodes of moderate stress, buying when others are selling and exploiting dislocations, which can smooth price discovery.^12,15

On the other side, public speeches and financial stability assessments caution that structural reliance on highly leveraged, short-term funded investors creates vulnerabilities under more severe stress.^4,10,16 The key point is conditional: hedge funds may be net providers of liquidity in mild to moderate turbulence, but can become forced sellers when funding conditions tighten or investor redemptions surge. The direction of their impact depends on the nature of the shock, the state of funding markets and the behaviour of end-investors in hedge fund products.¹⁸

Researchers at the Federal Reserve have documented how hedge funds cut back their US Treasury exposures during the March 2020 turmoil, driven primarily by liquidity management and redemption risk rather than direct constraints in repo markets.¹⁸ This suggests that even when funding terms do not worsen dramatically, internal risk limits and investor behaviour can trigger deleveraging. If a future episode combines funding stress, higher haircuts and larger redemptions, the magnitude of the unwind could be greater.

Another contested area concerns the adequacy of current regulatory and data frameworks. Some argue that improved margining practices, central clearing of repos and enhanced reporting requirements have materially reduced the risk of uncontrolled feedback loops, compared with pre-crisis conditions.^14,26 Others point out that many hedge funds operate through entities in jurisdictions with lighter reporting obligations, and that synthetic exposures via derivatives can be difficult to track on a consolidated basis.^4,7,17 International bodies and central banks are therefore calling for better monitoring of cross-border exposures, funding structures and correlated stress channels.^8,16,24

Strategic implications for central banks and regulators

For central banks, the strategic challenge is to reap the benefits of hedge funds’ participation in sovereign debt markets while containing the systemic vulnerabilities that arise from leverage and common strategies. Several lines of policy thinking are emerging.

First, authorities are investing in better data and analytical tools to identify pressure points in the changing financial system.^16,17 This includes enhanced dashboards for repo market conditions, metrics of leverage and concentration in hedge fund portfolios, and models that decompose systemic risk into contagion and common exposure components. By understanding where leverage is most concentrated and how it is funded, central banks can gauge the potential impact of shocks on sovereign markets and the broader system.

Second, there is a focus on strengthening market infrastructure. In Canada, plans to use new clearing infrastructure for domestic repo operations aim to reduce counterparty risk and improve transparency.^8,14 Central clearing and robust collateral management can mitigate some channels of contagion, though they do not eliminate risks associated with forced asset sales under stress. Authorities also stress the importance of resilient trading platforms and settlement systems, particularly given concerns about cyber risks and the possibility of AI-supported attacks on critical financial infrastructure.^10,20

Third, macroprudential policy discussions are considering whether existing tools, largely designed for banks, need adaptation for non-bank intermediaries. This might involve tighter standards for margining and haircuts in repos, sectoral leverage limits in particularly sensitive market segments, or the development of countercyclical tools that can ease funding strains during system-wide stress.^4,7,10,16 Any such measures must balance the desire for resilience with the need to preserve market liquidity and innovation.

Finally, authorities emphasise the role of private-sector risk management as the first line of defence.¹⁶ Hedge funds and their investors are being encouraged to develop more robust liquidity management frameworks, including stress tests that account for correlated funding shocks and the behaviour of other leveraged participants. Asset owners allocating capital to such strategies need to understand not only the standalone risk of the trades, but their potential contribution to system-wide dynamics.

Why the tension matters for the future of sovereign debt markets

The strategic tension in modern sovereign debt markets lies between the efficiency gains of highly leveraged, sophisticated trading and the systemic fragility that can arise when many actors pursue similar low-risk, high-leverage strategies funded through the same short-term channel. Sovereign bonds are no longer held predominantly by traditional buy-and-hold institutions; they are also the raw material for complex, scale-driven trading strategies executed by hedge funds operating across borders.^8,10,12,24

As global public debt remains high and governments continue to rely on bond markets to finance fiscal programmes, the importance of reliable market functioning will only grow. If key segments of sovereign markets are vulnerable to rapid, correlated unwind driven by repo market stress, the implications extend beyond trading desks. Monetary policy transmission, bank funding costs, risk-free benchmarks and the pricing of corporate and household borrowing all depend on stable sovereign curves.^2,10,14

Authorities do not seek to remove hedge funds from these markets; their participation brings liquidity, innovation and diversification. The objective is to ensure that systemic overlays created by leverage, common funding and position similarity are recognised and managed before they crystallise into severe market dysfunction. The debate will continue over the best mix of data, infrastructure, regulation and private risk management to achieve that outcome, but the underlying issue – the interaction between micro-level low-risk trades and macro-level systemic vulnerability – will remain at the centre of financial stability discussions.^4,10,16

 

References

1. https://www.youtube.com/watch?v=Ohg5Sav1kpw – https://www.youtube.com/watch?v=Ohg5Sav1kpw

2. Bank of Canada governor warns of growing risks to financial stability – 2026-03-04 – https://ca.finance.yahoo.com/news/bank-canada-governor-warns-growing-184831197.html

3. [PDF] Market operations and liquidity Provision at the Bank of Canada – https://elischolar.library.yale.edu/cgi/viewcontent.cgi?article=12384&context=ypfs-documents

4. OFR Monitor Shows Rising FX and Sovereign Debt Exposure – 2024-12-23 – https://www.financialresearch.gov/the-ofr-blog/2024/12/23/ofr-monitor-shows-rising-fx-and-sovereign-debt-exposure/

5. Tiff Macklem: New players, old risks – financial stability in a changing … – 2026-03-12 – https://www.bis.org/review/r260310c.htm

6. [PDF] Systemic Risk and Portfolio Diversification – Banque du Canada – 2021-10-13 – https://www.banqueducanada.ca/wp-content/uploads/2021/10/swp2021-50.pdf

7. The increasing role of hedge funds in Government of Canada bond … – 2025-10-03 – https://www.bankofcanada.ca/2025/10/staff-analytical-note-2025-22/

8. Bank of Canada warns of risks linked to non-bank players in debt … – 2026-03-04 – https://www.reuters.com/world/americas/bank-canada-warns-risks-linked-non-bank-players-debt-markets-2026-03-04/

9. New players, old risks: Financial stability in a changing landscape – 2026-03-04 – https://www.bankofcanada.ca/2026/03/new-players-old-risks-financial-stability-in-a-changing-landscape/

10. Hedge Funds’ Record $7T Sovereign Debt Holdings – Reddit – 2025-12-16 – https://www.reddit.com/r/bonds/comments/1pnnwim/hedge_funds_record_7t_sovereign_debt_holdings_a/

11. Overall assessment – Bank of Canada – 2026-05-28 – https://www.bankofcanada.ca/publications/financial-stability-report/financial-stability-report-2026/overall-assessment/

12. [PDF] Financial Stability Report-2026 – Bank of Canada – https://www.bankofcanada.ca/wp-content/uploads/2026/05/fsr2026.pdf

13. Hedge funds and government bond markets: Why is there a love … – 2025-07-16 – https://goghieas.substack.com/p/hedge-funds-and-government-bond-markets

14. Hedge funds and private credit pose stability risks, says Macklem – 2026-03-05 – https://www.centralbanking.com/central-banks/financial-stability/7975295/hedge-funds-and-private-credit-pose-stability-risks-says-macklem

15. [PDF] Canadian Repo Market Ecology – à www.publications.gc.ca – 2016-03-08 – https://publications.gc.ca/collections/collection_2016/banque-bank-canada/FB3-6-2016-8-eng.pdf

16. Hedge funds: good or bad for market functioning? – 2024-09-23 – https://www.ecb.europa.eu/press/blog/date/2024/html/ecb.blog20240923~d859db790b.en.html

17. Identifying pressure points in a changing financial system – 2026-03-04 – https://www.bankofcanada.ca/2026/03/identifying-pressure-points-in-a-changing-financial-system/

18. [PDF] Decomposing Systemic Risk: The Roles of Contagion and Common … – 2024-05-28 – https://www.bankofcanada.ca/wp-content/uploads/2024/05/swp2024-19.pdf

19. [PDF] Hedge Fund Treasury Trading and Funding Fragility – Federal Reserve – https://www.federalreserve.gov/econres/feds/files/2021038pap.pdf

20. Bank of Canada governor warns of high geopolitical risks and … – 2026-03-06 – https://www.facebook.com/groups/letstalkalbertaindependence/posts/2016588022272730/

21. Canada’s financial system resilient, says Bank of Canada – YouTube – 2026-05-29 – https://www.youtube.com/watch?v=JW7auwm5HJI

22. [PDF] SOVEREIGN DEBT CRISES AND VULTURE HEDGE FUNDS – https://bclawreview.bc.edu/articles/207/files/63a2b93920c4d.pdf

23. Bank of Canada says financial system is in good shape, but … – CBC – 2026-05-28 – https://www.cbc.ca/news/business/bank-of-canada-financial-stability-9.7215056

24. MARKET RISK POLICY OF THE BANKS IN CANADA – 2013-04-04 – https://papers.ssrn.com/sol3/Delivery.cfm/SSRN_ID2244848_code2002141.pdf?abstractid=2244848&mirid=1

25. The investor base for government and corporate bond markets – OECD – 2026-03-04 – https://www.oecd.org/en/publications/global-debt-report-2026_e9d80efd-en/full-report/the-investor-base-for-government-and-corporate-bond-markets_e68b90b3.html

26. Bank of Canada Gov. Macklem Warns of Excess Imbalances … – WSJ – 2026-06-23 – https://www.wsj.com/economy/central-banking/bank-of-canada-gov-macklem-warns-of-excess-imbalances-amid-shifting-financial-system-ea9ecfbc

27. Canadian Repo Market Ecology – IDEAS/RePEc – 2016-02-02 – https://ideas.repec.org/p/bca/bocadp/16-8.html

28. Barings Emerging Markets Sovereign Debt Fund – 2021-12-09 – https://www.barings.com/en-hk/individual/funds/public-fixed-income/barings-emerging-markets-sovereign-debt-fund

29. Financial stability in a changing landscape / La stabilité … – YouTube – 2026-03-04 – https://www.youtube.com/watch?v=NHCS4qI3XRI

30. Are Hedge Funds a Hedge for Increasing Government Debt Issuance? – 2025-02-02 – https://ideas.repec.org/p/bca/bocadp/25-07.html